<?php

function imageScale($rootPath, $imageName, $newImageName, $maxWidth, $maxHeight){

$imageInfo = GetImageSize($imageName);

/*
$memoryNeeded = Round(($imageInfo[0] * $imageInfo[1] * $imageInfo['bits'] * $imageInfo['channels'] / 8 + Pow(2, 16)) * 1.65);
$memoryLimit = str_replace("M", "", get_cfg_var('memory_limit')) * 1048576;
*/

$memoryNeeded = 0;
$memoryLimit = 1;

if($memoryNeeded >= $memoryLimit){
$result = 'The image file size or dimensions are too large.';
}

else{

// get image type and size

// list($width,$height,$type)=getimagesize($imageName);

$width = $imageInfo[0];
$height = $imageInfo[1];
$type = $imageInfo[2];

$imageType = image_type_to_mime_type($type);

// get new dimensions

if($width >= $height){

if($width > $maxWidth){
$newWidth=$maxWidth;
$newHeight=($height/$width)*$newWidth;
}

else{
$newWidth = $width;
$newHeight = $height;
}

}

else{

if($height > $maxHeight){
$newHeight=$maxHeight;
$newWidth=($width/$height)*$newHeight;
}

else{
$newWidth = $width;
$newHeight = $height;
}

}

if($newHeight > $maxHeight && $newWidth <= $maxWidth){
$newWidth=($newWidth/$newHeight)*$maxHeight;
$newHeight=$maxHeight;
}

if($newWidth > $maxWidth && $newHeight <= $maxHeight){
$newHeight=($newHeight/$newWidth)*$maxWidth;
$newWidth=$maxWidth;
}

// scale image

switch ($imageType) {
case 'image/gif':
    $src = imagecreatefromgif($imageName);
    $tmp=imagecreatetruecolor($newWidth,$newHeight);
    imagecopyresampled($tmp,$src,0,0,0,0,$newWidth,$newHeight,$width,$height);
    $newImageName.='.gif';
    $filename = $rootPath . $newImageName;
    imagegif($tmp,$filename);
    imagedestroy($src);
    imagedestroy($tmp);
    break;
case 'image/jpeg':
    $src = imagecreatefromjpeg($imageName);
    $tmp=imagecreatetruecolor($newWidth,$newHeight);
    imagecopyresampled($tmp,$src,0,0,0,0,$newWidth,$newHeight,$width,$height);
    $newImageName.='.jpg';
    $filename = $rootPath . $newImageName;
    imagejpeg($tmp,$filename,100);
    imagedestroy($src);
    imagedestroy($tmp);
    break;
case 'image/png':
    $src = imagecreatefrompng($imageName);
    $tmp=imagecreatetruecolor($newWidth,$newHeight);
    imagecopyresampled($tmp,$src,0,0,0,0,$newWidth,$newHeight,$width,$height);
    $newImageName.='.jpg';
    $filename = $rootPath . $newImageName;
    imagejpeg($tmp,$filename,100);
    imagedestroy($src);
    imagedestroy($tmp);
    break;
case 'image/bmp':
    $src = ImageCreateFromBMP($imageName);
    $tmp=imagecreatetruecolor($newWidth,$newHeight);
    imagecopyresampled($tmp,$src,0,0,0,0,$newWidth,$newHeight,$width,$height);
    $newImageName.='.jpg';
    $filename = $rootPath . $newImageName;
    imagejpeg($tmp,$filename,100);
    imagedestroy($src);
    imagedestroy($tmp);
    break;
default:
    $result = 'gif, jpg, bmp and png files only.';
    break;
}

}

$functionResult = array("image" => $newImageName, "error" => $result);

return $functionResult;

}

function ImageCreateFromBMP($filename)
{
 //Ouverture du fichier en mode binaire
   if (! $f1 = fopen($filename,"rb")) return FALSE;

 //1 : Chargement des ent?tes FICHIER
   $FILE = unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread($f1,14));
   if ($FILE['file_type'] != 19778) return FALSE;

 //2 : Chargement des ent?tes BMP
   $BMP = unpack('Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel'.
                 '/Vcompression/Vsize_bitmap/Vhoriz_resolution'.
                 '/Vvert_resolution/Vcolors_used/Vcolors_important', fread($f1,40));
   $BMP['colors'] = pow(2,$BMP['bits_per_pixel']);
   if ($BMP['size_bitmap'] == 0) $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset'];
   $BMP['bytes_per_pixel'] = $BMP['bits_per_pixel']/8;
   $BMP['bytes_per_pixel2'] = ceil($BMP['bytes_per_pixel']);
   $BMP['decal'] = ($BMP['width']*$BMP['bytes_per_pixel']/4);
   $BMP['decal'] -= floor($BMP['width']*$BMP['bytes_per_pixel']/4);
   $BMP['decal'] = 4-(4*$BMP['decal']);
   if ($BMP['decal'] == 4) $BMP['decal'] = 0;

 //3 : Chargement des couleurs de la palette
   $PALETTE = array();
   if ($BMP['colors'] < 16777216)
   {
    $PALETTE = unpack('V'.$BMP['colors'], fread($f1,$BMP['colors']*4));
   }

 //4 : Cr?ation de l'image
   $IMG = fread($f1,$BMP['size_bitmap']);
   $VIDE = chr(0);

   $res = imagecreatetruecolor($BMP['width'],$BMP['height']);
   $P = 0;
   $Y = $BMP['height']-1;
   while ($Y >= 0)
   {
    $X=0;
    while ($X < $BMP['width'])
    {
     if ($BMP['bits_per_pixel'] == 24)
        $COLOR = unpack("V",substr($IMG,$P,3).$VIDE);
     elseif ($BMP['bits_per_pixel'] == 16)
     { 
        $COLOR = unpack("n",substr($IMG,$P,2));
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     elseif ($BMP['bits_per_pixel'] == 8)
     { 
        $COLOR = unpack("n",$VIDE.substr($IMG,$P,1));
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     elseif ($BMP['bits_per_pixel'] == 4)
     {
        $COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
        if (($P*2)%2 == 0) $COLOR[1] = ($COLOR[1] >> 4) ; else $COLOR[1] = ($COLOR[1] & 0x0F);
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     elseif ($BMP['bits_per_pixel'] == 1)
     {
        $COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
        if     (($P*8)%8 == 0) $COLOR[1] =  $COLOR[1]        >>7;
        elseif (($P*8)%8 == 1) $COLOR[1] = ($COLOR[1] & 0x40)>>6;
        elseif (($P*8)%8 == 2) $COLOR[1] = ($COLOR[1] & 0x20)>>5;
        elseif (($P*8)%8 == 3) $COLOR[1] = ($COLOR[1] & 0x10)>>4;
        elseif (($P*8)%8 == 4) $COLOR[1] = ($COLOR[1] & 0x8)>>3;
        elseif (($P*8)%8 == 5) $COLOR[1] = ($COLOR[1] & 0x4)>>2;
        elseif (($P*8)%8 == 6) $COLOR[1] = ($COLOR[1] & 0x2)>>1;
        elseif (($P*8)%8 == 7) $COLOR[1] = ($COLOR[1] & 0x1);
        $COLOR[1] = $PALETTE[$COLOR[1]+1];
     }
     else
        return FALSE;
     imagesetpixel($res,$X,$Y,$COLOR[1]);
     $X++;
     $P += $BMP['bytes_per_pixel'];
    }
    $Y--;
    $P+=$BMP['decal'];
   }

 //Fermeture du fichier
   fclose($f1);

 return $res;
}

?>